J2K represents an upgrade of the JPEG format, including more features, such as supporting transparency and alpha channel, or lossless compression. J2K is part of a larger pack of improved JPEG extensions, known as JPEG2000, together with formats such as J2C, JPX, JPM or JP2. Most of these formats are compatible with mainstream image viewers, but do not enjoy the popularity of JPEG.
The quick and simple way to handle your files is to get a quality piece of software, such as reaConverter. This software is extremely efficient in managing a wide range of batch conversions. As you will soon realize, reaConverter will help you avoid spending countless hours trying to figure out how to convert multiple J2K files as once.
JPEG JPG PNG GIF TIFF TIF BMP ICO EMF WMF AI PDF EPS PS EPI WEBP WEBPLL JP2 PCX TGA DWG DWF DXF DGN WMZ CGM DRW SHP GBR PCT MIF PLT PCL SVG WPG CIN DCX DIS HRU MTV PRC RAD PIC RLA QRT SGI XBM XPM SWF CAL FAX FITS PSD PGM JXR BPG APNG DDS SVGZ CG4 FLIF AVIF